Yeam, Inhwa , Cavatorta, Jason , Ripoll, Daniel , Kang, Byoung-Cheorl , Jahn, Molly .
Functional dissection of highly conserved amino acid substitutions in the recessive potyvirus resistance genes encoding eIF4E.
Naturally existing variation in the eukaryotic translation initiation factor 4E (eIF4E) homolog encoded at the pvr1 locus in Capsicum results in recessive resistance against several potyviruses. Previously reported data indicates that the physical interaction between Capsicum-eIF4E and the viral genome linked protein (VPg) is required for the viral infection in the Capsicum-TEV pathosystem. In this study, the amino acid substitution G107R, one of several naturally existing substitutions in Capsicum-eIF4E at the pvr1 locus, was shown to be responsible for the interruption of in planta VPg-binding and also for the loss of in vitro cap-binding ability, the main function of eIF4E in the host. Over-expression of the Capsicum-eIF4E protein the G107R amino acid substitution (eIF4E-G107R) in Solanum lycopersicum also indicated that this polymorphism alone is sufficient for the acquisition of resistance against several TEV strains. The G107R change in Capsicum-eIF4E resulting in recessive resistance to TEV is also observed in other recessive resistance alleles identified in a number of plant species, indicating that a common amino acid substitution resulting in virus resistance in various plants has evolved independently in several different taxa. Additionally, engineered eIF4E alleles utilizing natural variation at this locus appear to be a useful method of generating disease resistance against all TEV isolates tested. Recessive resistance genes are widespread in plants, generally highly durable and now represent a new source of genetic variation for transgenic deployment.
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1 - Cornell University, Department of Plant Breeding and Genetics, Ithaca, NY, 14850, USA
2 - Cornell University, Department of Plant Breeding and Genetics
3 - Cornell University, Computational Biology Service Unit, Cornell Theory Center
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM